“…Given the limited reliability and validity of self-report measures of children’s dietary intake ( Kristal et al, 2005 , Livingstone et al, 2004 , Merson et al, 2017 , Rockett and Colditz, 1997 , Warren et al, 2003 ), the dependent variable, FV consumption at school, was measured by photographing children’s lunch trays before (“pre”) and after (“post”) they ate lunch. Photography has been used in the past to measure children’s diet ( Archundia Herrera and Chan, 2018 , McCloskey et al, 2019 , Elliott et al, 2021 , Winzer et al, 2018 ) and was combined, in this study, with the use of Digital Food Image Analysis (DFIA) software ( Todd et al, 2017 ). Due to the scope of this study (i.e., ∼30,000+ meals assessed from more than 2700 children × 4 waves of data collection × 3 days per wave) and the fast pace of the typical elementary school cafeteria ( Caruso and Rosenthal, 2020 ), photography was deemed the most practical and valid data collection method 1 ; rather than, for example, weighed plate waste.…”